Sometimes sharing content online can be tedious for the sharer and/or confusing for the recipient. For example, if Alice wants to share a webpage with Bob, Alice would share the uniform resource locator (URL) of that webpage or the webpage itself with Bob.
If Alice wants Bob to pay attention to a specific part of that webpage, Alice would need to describe the specific part and hope that Bob would be able to manually locate the specific part. For example, Alice would need to say “Look at the third sentence of the sixth paragraph,” or “see the lower left side of the second image,” or “the funny part is between minutes 2 to 4 of the video at the end of the page,” or “I think you will appreciate the segment between minutes 15 and 17 of the audio.”
Some webpages are long and/or packed with similar content. Even if Alice spends time and effort in describing the specific part of a webpage, Bob may not be able to locate it.